Electrical tuning device.



R. H. MARRIOTT. BIGTRIOAL TUNING DEVIGE. ArPLIoATIoN II'LBD JULY 7, 1909,

Patented Dec. 13, 1910.

2 SHEETS-SHEET l.

@Ui/knew@ R. H. MARRIOTT. ELECTRICAL TUNING DEVICE.

nPLIoATIol FILED JULY 7, 1909.

Patent-.ed Dee. 13,1910.

2 BHEETB-BHEET 2.

witnesses 33515 1143 Slim/mm1 .ments and combinations more ful lout hereinafter.

` NITED sTArEs PATENT oir-FICE.

nommer H. MARRIOTT, OF BROOKLYN, NEW YORK, ASSIGNOR TO NITED VlEtIlLEvSSy TELEGRAPH COMPANY, A CORPORATION 0F MAIINE.

ELECTRICAL 'r cierne DEVICE.

Specicaton ot Letters Patent. Application inea July 7, 1909. serial No. 506,424.

Patented Dec'. 13, 1910.

To all whom it may concern: l Be it known that I, ROBERT H. MAmz'Io'rr, a citizen of the United States, and a resiu dent 'of Brooklyn, Kings county, New York,

have invented certain new and useful-Improvements in Electrical Tuning Devices,

of which the following is a specification.

My invention relates' to a tuning appa-ratus for the high freuency transmission of electrical energy an particularlyto wireless telegra hs.

One of t provide a tuning apparatus in which the inL ductane and capacity .are simultaneously varied and in the same direction so that when the. inductance is decreased, the capacity is decreased and vice versa.

Another ob`ect o'f my invention is to pre vide a varia le inductance in which one portion of the inductance is fixed and another portion is mounted on a frame which swings toward and from the fixed coil.

Another object of my invention is to pro vide a tuning apparatus ofv the class .re-`

ferred to, in which a variable condenser is utilized, thesaid condenser comprising fixed and movable plates, the movable plate be ing mounted on a swingin frame, which, in the best embodiment of t e invention, also carries a coil forming part of a variable inductance.

With the above and other objects in view, my inventionconsists in the parts improve- Referring now to the drawings which are `attached to the specification and form a part thereof, Figure 1 illustrates diagrammatically the sending end of a wireless telegraph systememploying a variable inducta-nce, which may be constructed in accordance with my invention. Fig. 2 illustrates diagrammatically the receivln end of a wireless telegraph system emb ying my invention. Fig. 3 is a top plan view of a box containing a tuning apparatus constructed in accordance with my invention. Fig.4 is a cross-section throu h the box shownin Fig. 3. Fig. 5 is a etailed cross-section through the various layers of the condenser constructedl in accordance .with my invention. Fig. 6 is a lan view ofthe condenser. plate shown in igs. 4 and 5. Fig. 7 is a e objects of my invention is to y pointed diagrammatic view of the receiving circuit showing the variable condensers' and variable. inductances arran ed in circuit. Fig. 8 is a plan view of the oXes, one of which is shown in Fig. 3, which are arran ed to slide toward and .from each other. dig 9 shows a face view of one yof the coilsiapread apart. 44for clearness. Fig. 10 is a `detail showing the thin flat strip of which the. coil may bewound.

The sendingend of the system may be of the usual form. As illustrated, it includes` variable inductances so that when tuned, the aerial will send out a Wave-of definite frequency.` The aerialv 1 is connected with a coil .2. As shown, the 'outer end 3 of the coil-is connectedlte'the outer end t of a coil 5, the inner end of the coil 5 being con ynected to groundby means of the wire '6. The coil 5 is in inductive relation with the coil 7. As shown, the outer end 8 of the coil 7 is connected with the outer end 9 of a coil 10,the inner end of the coil 10 being connected to a spark knob 11, separated from a spark knob 12 by a gap 13.I The inner end of the ceil 7 isconnected by a wire 4111 .with one or more condensers 15, one late of the condenser being connected to the nob 12. The circuit just outlined including the spark ap 13 constitutes an oscillatory circuit. lt may be charged in any desired manner, as by means of an alternating cur* rent dynamo 16, having its terminals connected to the primary 17 of an induction coil, the circuit being closed through a telegraph key 18. The secondary, 19, of the induction coil has its terminals connected `with the oscillatory circuit, as indicated. When the telegraph key 18 is closed, the oscillatory circuit, includingI the spark a 13 is charged and becomes the source o igh frequency oscillations which are inductively transmitted to the aerial 1, the aerial sending out waves. As shown in Fig. 2, thereceiving circuit consists of an aerial 20 which may be connected to the inner end of a coil 21, the outer end 22 of the coil bein then connected b a wire to the outer en 23. of a. coil 211. hecoils 21 and 211 are in inductive relation, so that the self-induction of the pair of coils may be varied by moving o ne coil, as, for example, the coil 24 with relation to the coil 21. The inner end of the coil 24 is connected by wire 25 through a variable condenser 26 to ground. The coils 27 is connected to the' outer end of the coil 28,-the two inner ends ofthe coils 27 and 28. being connected to oints in the local receiving circuit. As i ustrated, they "are connected on opposite sides. of a variable condenser 44, 46, so that the local circuit 27, 28, 44, 46 constitu`tes a receivin circuit of high frequency oscillations Whic ceiving circuit. As illust-rated, one terminal of the receiver is connected to the'point- 31 and the other terminal of the receiver is connected to one plate of a condenser 32, the other plate of the condenser being connected at 33 with the receiving circuit.

When the oscillations in the receivin circuit develop electrical energy of s cient amount, the detector 30 res onds and allows an -indicatin current to ow through the telephone. he tele hone .circuit is connected about the wire ess detector' 30 in any suitable manner. As illustrated, the 4telephone 33 Which is shown as a head telephone 1s connected by Wires 34 to a telephone circuit including a potentiometer 35, the-latter being connected at 36 to one side of the de- A tector and at 37 to one side of the telephone. p The battery 38 has its terminals connected to the potentiometer, one terminal 39 sliding along the otentiometer to vary the drop in potential t rough the potentiometer as `will be understood.

Referring noviT to Figs. 3 to 9, the tuning apparat-us forming part of my invention will be readily understood. It is preferably lconstructed in du licate, cach set be.

lng contained lin a suita le box 40,-55. A fixed frame 41, which, in the best embodiment-of the inventioncloses the front of the box, carries the coil 27. This coil iswvound as a fiat disk, (the com anion coil 28 bei shown particularly in 9 and 10), add consistspreferabl ofat in ribbon of wire mounted on the aceof the frame 41. By constructing the coil of thin ribbonlike wire, the resistance of the coil for the-same number of turns, that is, with a given self-induction is reducedver what it would be were a vroundwire used. "A movable frame -42 carrying the coil 28,'Which is constructed -like the coll 27 is mounted within the box.

It is so mounted as to swing about an axis, which, as illustrated, is outside of the fixed coil. Themeans for mounting the swinging coil may be Widely varied., In the particular embodiment of the invention illustrated, the

` axis .about which the coil swings is a fixed' axis or pivot 43 located inside4 of the box 40,

vcoil 27.

can be tuned.. A Wave detector 30 is connected to thereto which lpivot the' frame 42 is secured. The coil 28 t us swings toward and from the In the best embodiment of the invention, I

make use of a variable condenser, one plate of whichl is moved when the coil 28 moves.

This occurs in such a manner thatpas the self-induction of the local coils is increased, by their separation, the capacity of the associated condenser is increased by the ap-f proach of its condenser plates, and vice versa, as the self-induction of the local coils diminishes, the capacity of the condenser diminishes. The wave ength lto which the circuit is tuned, is increased or diminished quickly, the change -in both self-induction and capacitycoperating. In the particular embodiment of the invention illustrated, the coil' 28 and the condenser plate are mounted on the frame 42; onA opposite 'sides thereof. I construct the condenser by mounting upon the frame 42, yielding material such as paper 43 on which a sheet of foil 44,"form- 1n the condenser plate is mbunted. .On top l o the foil, I secure a sheet of insulating material such as mica '45. The xed condenser plate in the particular embodiment of the invention illustrated is mounted upon the side of the box 40. It is mounted upon yielding material, such as paper and may covered with mica.

In the best embodiment of the invention and in order to a'void eddy currents, which waste ener and which may-be introduced in the con enser plates by the inductive action'of the coil 28, I slit the foil of one or both condenser plates, as illustrated 'in Fi 6. This prevents the circulation of eddgy currents around the plates. v

In order to secure-compactness of construction, I prefer to locate another vari-- able condenser within the box 40. The fixed plate of the condenser is mounted .upon the support 47, carrying yielding-material 48,

. on which the condenser plate 49 is mounted.

Thel condenser plate 49 may be provided witha coating of insulati material. The removable plate of the con enserjs carried by` aframe 50, which in turn carries ielding material 51supporting the con enser plate 52. The screw 53 which may be turned by the Vknob 54 willcause the frame 50 to advance the condenser plate 52 toward and fromjits companion plate 49.so as to vary the capacity.

ferring now to Fig. 8, it will be lob -servedthat boxes 40, 5,5 are used, which are alike in -all substantial particulars. These may be connected b'y guiding means 56, 57, 58,| so that the faces 41, 59 of the -boxes, which carry the fixed coils, can b brought in juxtaposition or can be widely arated. The guiding means may be omitted if de-' sired, without interfering vwith this capa.

bility of adjustment. Knobs 60 and 61 '130 the circuit.

in g post mecs which are attached to the swinging frames 42 carrying the movable coils, permit the positioning of the movable coils with relation to the fixed coils, as will bereadily understood.

The arrangement of the devices in the receiving circuits will be clear from an examination of Fig. 7. The receiving aerial is connected to a Wire leads to preferably the inside 63 of the fixed coil 2l. The outside of the coil 21 is preferably connected with the outside of the movable coil 24. The windings yof the coils 21 and 24 are so arranged thatthe high frequency current passing through the coil 2l will pass in the opposite direction through the coil 24,-so that when the coils are in juxtaposition, the self-induction of the coils is substantially neutralized; as for example, when the movable coil is fully open the in ductance may be 400 micro henries and when closed micro henries. From the inner end of thecoil 24, a Wire passes to a suitable binding post 64 or point of connection with The movable frame 420 carryn ingthe condenser plate 440, which swings about the pivot 430 also carries the coil 24. The condenser plate is likewise connected with .the binding post 64 by wire 65. The fixed plate 46() of the condenser is connected by means of a wire 66 to binding post 67 and then by ground wire 68 to the ground. The wireless oscillations coming in on the receiving aerial 20 will thus pass in succession through the coils 21., 24, condenser 420, 460 and then to ground. The adjustable con denser 490, 520 may have its plates connect-H ed at 67 and 69 in parallel with the conr denser Li40, 460, or it may be connected in the circuit in any suitable manner. Turning now to the local circuit connected with the receiver, the fixed coil 27 has its inner terminal connected by means of Wire 70 with binding post 7l, the outer end of the coil 27 being connected to the outer end of the coil 2S, the coils heilig wound, so that the inductive effects are substantially neutralized when the coils are together. The inner end of the coil 28 connects by Wire with a bind- 7 2 which is connected to the mov able condenser plate 44. The fixed. con denser plate 46 is'connected to the binding post '71, completing the tuning circuit through the coils 27 and-.28 by a Wire 73 and binding post 74. The eondenser`48, 52 has its coatings connected to binding posts 74, 75, so as to be in parallelwith the condenser 44, 46, but other arrangements of the condenser 48, 52 may be\made. The circuit containing the detector 30 is connected to binding posts 75, 71, a condenser 32 being preferably connected in one of the leads. The potentiometer 35, battery 38, telephone are connected about, that is on opposite sides of the detector B0, as indicated. When the binding post 62 from which a Wireless oscillations lsurging lthrough the local tuned circuit are suiiiciently strong to cause the detector 30 to respond, the poten tionieter sends its current through the detector and gives the signal in the telephone.

Instead of the inductive connection illusA trated in Fig. 2, the receiving aerial circuit may be connected 'With the local receiving circuit conductively. As illustratethl have shown in dotted lines Wires 80, 8l which may be connected by the switch 82 so as to conductively connect the aerial circuit with the` local circuit containing the coils 27,. 28. l

What I claim and dcsireto secure by Letters l)atent is zl. A tuning device for the high frequency transmission of electrical energy comprising a fixed coil 'mounted on the frame,.a coil mounted on a movable' frame, a'condenser plate mountedonthe opposite side of said movable frame, and a fixed support carrying another condenserplate, with which the 'tormer cooperates to form a condenser of variable capacity. c y

2. A tuning apparatus tor the high trequency transmission of electrical energ comprising a box, a frame closing the mouth of the box, a xed frame, a movable coilniounted 'to swing Within said box toward and from saidixed coil, a condenser plate carried by one side of said box, adjacent to said movable coil and coperating With'said fixedfcondenser plate.

3. A tuning apparatus for the high trequency transmission' of electrical energy comprising a box, alixed trame closing the mouth of said box, a coil carried by the face of said frame, and movable toward and from said fixed coil, yielding material car` ried bythe back of said movable frame, a condenser plate mounted thereon, yielding material carried by the side of said box, a condenser plate carried thereon, said condenser plates constituting a condenser ol variable capacity.

4. In a Wireless a movable condenser plate mounted y telegraph tuning system,

coil mounted on said I the combination of an aerial circuit, a local circuit, a fixed coil in each of said circuits in inductive relation With each other, said fixed coils `being adapted to be placed and maintained at did'erent fixed distances'irom each other, a lmovable coil in said local circuit, means for adjusting the position of each movable coil with relation to the corresponding fixed coil,` two of the ends of said local coils being connected together and the remalnlng ends of the local coils being lconnected each to a point in said local circuit.

5. In ,a Wireless telegraph tuning system, the combination of an aerial circuit, a local circuit, a fixed coil in each of said circuits in inductive relation With the other, means for adjusting said fixed coils, said fixed coils being adjustable toward and from each other, so as to adjust and fix the inductive relationbetween them, a movable coil in said local circuit, said movable coil lyin wholly outside ofthe plane of the fixed co' and be` ing adjustable toward and from said fixed coil, two of the vends of said coils in a local Icircuit bei connected together and the remaining en s of the local coils being connected each toa binding post so as to permit their connection with the loca-l circuit.

6. In a wireless telegraph tun' system," the combination of an aerial circuit, a local circuit, a xed coil n eachof said circuits` in inductive. relation with each other, apivoted coil in said local circuit movable toward and lfrom said fixed coil, two of the ends of said local coils being connectedtogether and the remaining 'ends of the local coils being lconnected each to a binding their connection to the ocal circuit.

7 In a wireless telegraph tuning system,

'tween them, a movable coil being postso as to permit c the combination of an aerial circuit, a local circuit, a llat frame, a lxed coil mounted onthe face of said frame and included in said aerial circuit, a -fiat frame ca coil included in said local circuit, said fixed coils being adjustable toward and .from each other so as to vary the inductive relation beadapted to aboutanmxis toward and from the vfixed coil in the local two of the ends of said local coils being conn together and their remaining ends being connected each to a int in the local circuit.

In testimony whereof, I have signed my name to this specification, inthe presence' of WO we" `ROBERT H. MARRIOTT.

i Wi: A

H. M. Sums,

W. L. Blaauw.

ing a fixed 

